Technical Field
The present invention relates to a photocatalyst, and the method of using this catalyst in water purification and photovoltaic systems. More specifically, the present invention relates to a zinc-based nanohybrid containing zinc oxide nanostructures, zinc phthalocyanine molecules and bridging ligands between the nanostructures and the zinc phthalocyanine molecules.
Description of the Related Art
The “background” description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.
The choice of photosensitizers is crucial in light-harvesting applications such as dye-sensitized solar cells (DSSC) and visible light photocatalysis (VLP). Polypyridyl ruthenium complexes are commonly used because they absorb strongly in the ultraviolet (UV) and visible region (M. Grätzel, Acc. Chem. Res. 42 (2009) 1788-1798; B. Oregan, M. Gratzel, Nature 353 (1991) 737-740; A. Makhal, S. Sarkar, T. Bora, S. Baruah, J. Dutta, A. K. Raychaudhuri, S. K. Pal, J. Phys. Chem. C 114 (2010) 10390-10395; C.-Y. Chen, J.-G. Chen, S.-J. Wu, J.-Y. Li, C.-G. Wu, K.-C. Ho, Angew. Chem. Int. Ed. 47 (2008) 7342-7345—each incorporated herein by reference in its entirety). However, they have a low absorption in the near infrared (IR) region. Therefore, extending the response of the photosensitizers to the near IR region is essential to improve the efficiency of light-harvesting devices (M. Garcia-Iglesias, J.-J. Cid, J.-H. Yum, A. Forneli, P. Vazquez, M. K. Nazeeruddin, E. Palomares, M. Gratzel, T. Torres, Energy Environ. Sci. 4 (2011) 189-194—incorporated herein by reference in its entirety). Phthalocyanines are a class of aromatic macrocyclic tetradentate ligands, and they have been used in polymer-based DSSC to complement the absorption of the polymer in the red region of the solar spectrum (S. D. Oosterhout, M. M. Wienk, S. S. van Bavel, R. Thiedmann, L. Jan Anton Koster, J. Gilot, J. Loos, V. Schmidt, R. A. J. Janssen, Nat Mater 8 (2009) 818-824—incorporated herein by reference in its entirety). They coordinate to metal cations, forming metallophthalocyanines. Zinc phthalocyanines are a class of phthalocyanines whose main electronic features are explained using density function theory (DFT) (G. Mattioli, C. Melis, G. Malloci, F. Filippone, P. Alippi, P. Giannozzi, A. Mattoni, A. Amore Bonapasta, J. Phys. Chem. C 116 (2012) 15439-15448—incorporated herein by reference in its entirety). The phthalocyanine ligands in the prior art are usually chemically modified to add functional groups to improve their photocatalytic and physical properties (G. de la Torre, C. G. Claessens, T. Torres, Chem. Commun. (2007) 2000-2015; L. Giribabu, C. Vijay Kumar, V. Gopal Reddy, P. Yella Reddy, C. Srinivasa Rao, S.-R. Jang, J.-H. Yum, M. K. Nazeeruddin, M. Gräzel, Sol. Energ. Mat. Sol. Cells 91 (2007) 1611-1617; S. Mori, M. Nagata, Y. Nakahata, K. Yasuta, R. Goto, M. Kimura, M. Taya, J. Am. Chem. Soc. 132 (2010) 4054-4055; J. He, A. Hagfeldt, S.-E. Lindquist, H. Grennberg, F. Korodi, L. Sun, B. Åkermark, Langmuir 17 (2001) 2743-2747; G. Bottari, G. de la Tone, D. M. Guldi, T. Tones, Chem. Rev. 110 (2010) 6768-6816; M. K. Nazeeruddin, R. Humphry-baker, M. Gräzel, D. Wöhrle, G. Schnurpfeil, G. Schneider, A. Hirth, N. Trombach, J. Porphyrins Phthalocyanines 03 (1999) 230-237—each incorporated herein by reference in its entirety). These ligands often involve tedious multi-step syntheses (P. Y. Reddy, L. Giribabu, C. Lyness, H. J. Snaith, C. Vijaykumar, M. Chandrasekharam, M. Lakshmikantam, J. Yum, K. Kalyanasundaram, M. Gratzel, M. K. Nazeeruddin, Angew. Chem. Int. Ed. 46 (2007) 373-376; J. He, G. Benkö, F. Korodi, T. Polivka, R. Lomoth, B. Akermark, L. Sun, A. Hagfeldt, V. Sundström, J. Am. Chem. Soc. 124 (2002) 4922-4932—each incorporated herein by reference in its entirety).
Conventional water disinfection methods, such as chlorination and ozonization, have limitations because they are expensive, time-consuming, and produce harmful by-products. In order to overcome these inadequacies, many efforts have been carried out to develop more effective water disinfection methods that are environment friendly, cost effective, and highly efficient (S. Malato, P. Fernández-Ibáñez, M. I. Maldonado, J. Blanco, and W. Gernjak, Catalysis Today 147 (2009) 1-59; Jori, M. Magaraggia, C. Fabris, Journal of Environmental Pathology, Toxicology and Oncology 30 (2011) 261-271; M. Muruganandham, R. P. S. Suri, Sh. Jafari, International Journal of Photoenergy 2014 (2014) Article ID 821674, 21 pages—each incorporated herein by reference in its entirety). Towards this goal, photosensitizers, such as porphyrins and phthalocyanines, have been explored for the degradation and removal of toxins, dyes, and other unwanted impurities from water sources (S. Malato, P. Fernández-Ibáñez, M. I. Maldonado, J. Blanco, and W. Gernjak, Catalysis Today 147 (2009) 1-59; P. Kluson, M. Drobek, S. Krejcikova, Applied Catalysis B: Environmental 80 (2008) 321-326—each incorporated herein by reference in its entirety). Upon light irradiation in the presence of oxygen, photosensitizers produce reactive oxygen species (ROS) that are capable of killing bacteria, fungi, and viruses and cause the oxidation of unwanted contaminants present in water (S. Malato, P. Fernández-Ibáñez, M. I. Maldonado, J. Blanco, and W. Gernjak, Catalysis Today 147 (2009) 1-59; G. Joni, M. Magaraggia, C. Fabris, Journal of Environmental Pathology, Toxicology and Oncology 30 (2011) 261-271; M. N. Chong, B. Jin, C. W. K. Chow, and C. Saint, Water Research 44 (2010) 2997-3027; M. C. DeRosa and R. J. Crutchley, Coordination Chemistry Reviews 233-234 (2002) 351-371; {hacek over (Z)}. Luk{hacek over (s)}ienė, Food Technology and Biotechnology, 43 (2005) 411-418—each incorporated herein by reference in its entirety). However, these phthalocyanine molecules, similarly to those used in DSSC, require multi-step syntheses in order to incorporate functional groups in the fused benzene rings to improve their solubility in water.
In view of the forgoing, the objective of the present invention is to provide a zinc metallophthalocyanine-based nanohybrid, a substrate and a dye decontaminating device containing the nanohybrid, and a method for degrading a dye using the nanohybrid.